1. Field of the Invention
The present invention relates to systems and methods for activating functionality in a set-top box and in particular to a method and system for a feature authorization scheme for activating set-top box capabilities.
2. Description of the Related Art
In recent years, there has been an increase in the interest and use in cable and satellite television services. Set-top boxes (STB) utilized to receive such services may also be used to offer additional advanced functionality that may require a monthly subscription. For example, personal video recording (PVR) and video games may be offered through the STB by a broadcast provider. In order to provide such STB services to customers of multi-channel programming, it is advantageous to have a method of activating services in a manner that is flexible and secure.
In the prior art, PVR service activation has utilized a two-way communication (such as by phone modem). For broadcast satellite receivers, it is advantageous if the STB service could be activated by one-way communication over the satellite.
It is especially advantageous if such a system were able to utilize the existing conditional access infrastructure for broadcast service authorization and billing using a secure smart-card in the STB. Such a system should preferably allow for flexible activation of a multitude of set-top box services with a similar level of security as the broadcast services. The prior art fails to provide such a method or capability. These problems may be better understood by a description of prior art conditional access services.
Broadcast service activation in the prior art involves authorization to receive an encrypted broadcast service, such as subscription television channels, or pay-per-view movie programs, or music or data services. These broadcast services are generally encrypted at the broadcast headend, and the conditional access controls include service activation and entitlement checking and the delivery of a decryption key (or control word CW) for the correct decryption of such broadcast services.
Conditional access for digital broadcast satellite (DBS) systems usually use a conditional access module (CAM) such as a smart card, for broadcast service activation. Authorization for services provided by the CAM are received by the CAM in over-the-air conditional access packets (CAPs). Broadcast services and programs have associated program access data (PAD) that specifies the services required for reception of that program, as well as possible limitations (e.g., regional blackout, parental rating controls). The PAD and CW for current programs are delivered via control word packets (CWP) to the CAM. The CAM checks the PAD, and if authorized, delivers the CW to the STB for program decryption.
The PAD for a future program is delivered to the CAM via program information packet (PIP) to allow pre-purchase of impulse pay-per-view (IPPV) programs or for checking authorizations before the broadcast (e.g., for guide “coloring”). The CAM checks the future PAD and responds to the PIP test with the CAM status regarding the future program, for example “authorized”, “not authorized”, “blacked out” or “IPPV allowed”.
STB functions and services generally do not involve an encrypted stream of information, but merely the activation of advanced capabilities in the STB. Authorization for services provided by the STB may be activated in the CAM by over-the-air CAPs, and such authorizations may be checked by the STB via PIP test of the CAM.
The following description illustrates the service activation of DIRECTV DVR™ service in a STB in the prior art using CAPs. Except for the STB's initial factory state (DIRECTV DVR Service State 0=“unknown”), the STB could only be in one of two states, DVR (digital video recorder) service authorized (e.g., DIRECTV DVR Service State 3=“good”) and DVR service not authorized (e.g., DIRECTV DVR Service State 13=“declined”). Authorization for DIRECTV DVR service activation is provided by CAP authorization of a DVR service identifier in the CAM, which the STB checks via a PIP test “Is DVR service authorized?” for which the CAM status is “authorized” or “not authorized”.
The PIP for testing DIRECTV DVR Service is encapsulated within a vendor object (VO) sent via the advanced program guide (APG) stream, and stored in the APG database or hard disk drive of the STB. If a new version of the VO is received, and on a periodic daily basis, the PIP test is performed by the STB to check for the activation status of the DIRECTV DVR service. This check can result in the service being turned on or turned off.
If the service is off, and the user attempts to access a DVR function, the STB rechecks whether the service has been activated using the PIP. This check may result in the service being turned on or remaining off.
Upon power-up of the STB, or upon card removal or insertion, the service state reverts to off (i.e., service not active). The STB must test the CAM using the PIP to check whether the service is authorized. Similar to above, the check may result in the service being turned on or remaining off.
Thus, in view of the above description of the prior art, the only verification that occurs to activate STB functionality is that of periodically checking to determine if the CAM has been authorized for a particular service. In comparison, the broadcast television services require the CAM to supply a frequently changing decryption CW.
The present invention addresses the above-described problems of the prior art and provides verification rules to activate STB functionality. This invention also allows these verification rules and the corresponding STB functions to be flexibly defined by over-the-air feature authorization messages.